汽车转向系统脉动噪音分析与试验研究

谐振管是降低汽车转向系统流体脉动噪音的重要部件,如何选择合适长度的谐振管进行降噪测试非常重要。以某轿车液压助力转向系统为研究对象,通过对转向高压管结构的分析及1/4波长消音管基本参数的计算,制作9种测试样件,采集其频谱噪声数据、油管进出油口压力脉动数据及初选方案的噪音特性曲线,结果表明,谐振管的最佳降噪长度介于根据谐振一次频率、二次频率计算的理论长度之间;谐振管长度与噪音值不成线性正比关系,可以计算结果为依据制作多种样件进行台架测试选取最优方案。

轿车动力转向泵脉动噪音优化

通过理论分析结合试验验证的方式,对液压转向系统中的最大的噪音源—转向泵,进行了脉动噪音分析,并通过调试高压管衰减噪音,提高了车辆舒适性。

变排量压缩机脉动噪音分析和优化

气流脉动是引起斜盘式变排量压缩机噪音的主要原因。文章通过对一类搭载至整车的压缩机产生的气流脉动噪音问题进行分析,为汽车空调气流脉动噪音控制制定出有效的解决方案,从而为提升汽车空调的乘坐舒适性奠定基础。

空调器排气管消音器的选型设计与应用

空调器压缩机运行时,冷媒在管路系统内的压力以一定的频率激励管路系统而产生的脉动噪音,即空调行业所说的压缩机传响。本文针对用户抱怨大的压缩机传响产生的"嗡嗡"声问题,在压缩机排气管上设置适宜的消音器,并通过理论计算和实验研究对消音器进行选型,进而通过实验研究得出了一种利用频谱分析技术并通过在排气管上增加消音器来改善空调噪音的方法,有效改善了空调器的噪音品质。

Characteristic and Mechanism of Pressure Fluctuation Caused by Self-Induced Oscillation of Supersonic Impinging Jet

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow os- cillation occurs. This oscillation depends on the pressure ratio in the flowfield, the position of an obstacle and is related with the noise problems of aeronautical and other industrial engineering. The characteristic and the mechanism of self-induced flow oscillation, have to be clarified to control various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of an oscillation have to be more cleared to control the oscillation. This paper aims to clarify the effect of the pressure ratio and the obstacle position and the mechanism of self-induced flow oscillation by numerical analysis and experiment, when the underexpanded su- personic jet impinges on the cylindrical body. From the result of this study, it is clear that occurrence of the self-induced flow osciUation depends on the pressure balance in the flowfield.